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-rw-r--r--Modules/CheckSymbolExists.cmake101
1 files changed, 101 insertions, 0 deletions
diff --git a/Modules/CheckSymbolExists.cmake b/Modules/CheckSymbolExists.cmake
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index 000000000..e6e677d4f
--- /dev/null
+++ b/Modules/CheckSymbolExists.cmake
@@ -0,0 +1,101 @@
+# - Check if a symbol exists as a function, variable, or macro
+# CHECK_SYMBOL_EXISTS(<symbol> <files> <variable>)
+#
+# Check that the <symbol> is available after including given header
+# <files> and store the result in a <variable>. Specify the list
+# of files in one argument as a semicolon-separated list.
+#
+# If the header files define the symbol as a macro it is considered
+# available and assumed to work. If the header files declare the
+# symbol as a function or variable then the symbol must also be
+# available for linking. If the symbol is a type or enum value
+# it will not be recognized (consider using CheckTypeSize or
+# CheckCSourceCompiles).
+# If the check needs to be done in C++, consider using CHECK_CXX_SYMBOL_EXISTS(),
+# which does the same as CHECK_SYMBOL_EXISTS(), but in C++.
+#
+# The following variables may be set before calling this macro to
+# modify the way the check is run:
+#
+# CMAKE_REQUIRED_FLAGS = string of compile command line flags
+# CMAKE_REQUIRED_DEFINITIONS = list of macros to define (-DFOO=bar)
+# CMAKE_REQUIRED_INCLUDES = list of include directories
+# CMAKE_REQUIRED_LIBRARIES = list of libraries to link
+
+#=============================================================================
+# Copyright 2003-2011 Kitware, Inc.
+#
+# Distributed under the OSI-approved BSD License (the "License");
+# see accompanying file Copyright.txt for details.
+#
+# This software is distributed WITHOUT ANY WARRANTY; without even the
+# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the License for more information.
+#=============================================================================
+# (To distribute this file outside of CMake, substitute the full
+# License text for the above reference.)
+
+INCLUDE("${CMAKE_CURRENT_LIST_DIR}/CMakeExpandImportedTargets.cmake")
+
+
+MACRO(CHECK_SYMBOL_EXISTS SYMBOL FILES VARIABLE)
+ _CHECK_SYMBOL_EXISTS("${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/CheckSymbolExists.c" "${SYMBOL}" "${FILES}" "${VARIABLE}" )
+ENDMACRO(CHECK_SYMBOL_EXISTS)
+
+MACRO(_CHECK_SYMBOL_EXISTS SOURCEFILE SYMBOL FILES VARIABLE)
+ IF("${VARIABLE}" MATCHES "^${VARIABLE}$")
+ SET(CMAKE_CONFIGURABLE_FILE_CONTENT "/* */\n")
+ SET(MACRO_CHECK_SYMBOL_EXISTS_FLAGS ${CMAKE_REQUIRED_FLAGS})
+ IF(CMAKE_REQUIRED_LIBRARIES)
+ # this one translates potentially used imported library targets to their files on disk
+ CMAKE_EXPAND_IMPORTED_TARGETS(_ADJUSTED_CMAKE_REQUIRED_LIBRARIES LIBRARIES ${CMAKE_REQUIRED_LIBRARIES} CONFIGURATION "${CMAKE_TRY_COMPILE_CONFIGURATION}")
+ SET(CHECK_SYMBOL_EXISTS_LIBS
+ "-DLINK_LIBRARIES:STRING=${_ADJUSTED_CMAKE_REQUIRED_LIBRARIES}")
+ ELSE(CMAKE_REQUIRED_LIBRARIES)
+ SET(CHECK_SYMBOL_EXISTS_LIBS)
+ ENDIF(CMAKE_REQUIRED_LIBRARIES)
+ IF(CMAKE_REQUIRED_INCLUDES)
+ SET(CMAKE_SYMBOL_EXISTS_INCLUDES
+ "-DINCLUDE_DIRECTORIES:STRING=${CMAKE_REQUIRED_INCLUDES}")
+ ELSE(CMAKE_REQUIRED_INCLUDES)
+ SET(CMAKE_SYMBOL_EXISTS_INCLUDES)
+ ENDIF(CMAKE_REQUIRED_INCLUDES)
+ FOREACH(FILE ${FILES})
+ SET(CMAKE_CONFIGURABLE_FILE_CONTENT
+ "${CMAKE_CONFIGURABLE_FILE_CONTENT}#include <${FILE}>\n")
+ ENDFOREACH(FILE)
+ SET(CMAKE_CONFIGURABLE_FILE_CONTENT
+ "${CMAKE_CONFIGURABLE_FILE_CONTENT}\nint main(int argc, char** argv)\n{\n (void)argv;\n#ifndef ${SYMBOL}\n return ((int*)(&${SYMBOL}))[argc];\n#else\n (void)argc;\n return 0;\n#endif\n}\n")
+
+ CONFIGURE_FILE("${CMAKE_ROOT}/Modules/CMakeConfigurableFile.in"
+ "${SOURCEFILE}" @ONLY IMMEDIATE)
+
+ MESSAGE(STATUS "Looking for ${SYMBOL}")
+ TRY_COMPILE(${VARIABLE}
+ ${CMAKE_BINARY_DIR}
+ "${SOURCEFILE}"
+ COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS}
+ CMAKE_FLAGS
+ -DCOMPILE_DEFINITIONS:STRING=${MACRO_CHECK_SYMBOL_EXISTS_FLAGS}
+ "${CHECK_SYMBOL_EXISTS_LIBS}"
+ "${CMAKE_SYMBOL_EXISTS_INCLUDES}"
+ OUTPUT_VARIABLE OUTPUT)
+ IF(${VARIABLE})
+ MESSAGE(STATUS "Looking for ${SYMBOL} - found")
+ SET(${VARIABLE} 1 CACHE INTERNAL "Have symbol ${SYMBOL}")
+ FILE(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
+ "Determining if the ${SYMBOL} "
+ "exist passed with the following output:\n"
+ "${OUTPUT}\nFile ${SOURCEFILE}:\n"
+ "${CMAKE_CONFIGURABLE_FILE_CONTENT}\n")
+ ELSE(${VARIABLE})
+ MESSAGE(STATUS "Looking for ${SYMBOL} - not found.")
+ SET(${VARIABLE} "" CACHE INTERNAL "Have symbol ${SYMBOL}")
+ FILE(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
+ "Determining if the ${SYMBOL} "
+ "exist failed with the following output:\n"
+ "${OUTPUT}\nFile ${SOURCEFILE}:\n"
+ "${CMAKE_CONFIGURABLE_FILE_CONTENT}\n")
+ ENDIF(${VARIABLE})
+ ENDIF("${VARIABLE}" MATCHES "^${VARIABLE}$")
+ENDMACRO(_CHECK_SYMBOL_EXISTS)